Automatic burette.



STANLEY D. BEARD, or sHELToN, CONNECTICUT.

AUTOMATIC BURETTE.

Specification of Letters Patent.-

PatentedNov. 9, i969.

iippucmqnsiea February e, i909. serial No. 475,849.

To all4 whom 'it may concern:

Be it known that I, STANLEY D. BEARD, a citizen of the United States, residing at Shelton, county of` Fairfield, State of Connecticut, have invented a new andV useful Automatic Burette, of which the follow/ing is a speciication. f

The 'ordinary burette provides for supply-v ing accurately a predetermined quantity of Huid, but has no means for enabling' it to beV kept in a condition for contlnuous re eat/ed` use; that is, it must be filled' an then` construction and combination of parts substantially as hereinafter described and claimed. i

.Dit the accompanying drawings Figiire 1 is a side elevation, partlyin section of a de-' vice or apparatus embodying thel invention. Fig. 2 is a plan View of thc'same, with the upper connections between the two heads removed. Fig. 3 is a detail elevation of thej left hand head shown in Fig. `1,'looking from the inside.

Similar reference characters indicate the same or similar parts in all of the views.

The barrel 10 of thc deviceypreferably of glass and graduated in any suitableffinanner and degree, is provided with two heads 11 and 12 which maybe of any suitable metal.

that will not be affected by the character of the' Huid being assed through the same. These heads may'lhe connectedv tightly to the ends of the barrel by any suitable means. I have illustrated elampin rods 13 passed through the heads and provided with nuts 14 as the means for holding the heads and barrel together, said heads having hub portions which slightly enter the ends of the barrel, gaskets 15 being employedl at the ends of the barrel to make iuid tight joints.

Each head is formed with o positely projecting nipples 16 said nipples ing tubular and connecting by ports Awith the interior of the barrel. The ports of theA head 11 pref-v Aportion of the hu erably cross each other so that the port 17 from the upper ni ple will lead'to the lower b) which enters the barrel, while the port 18 connects the upper portion of the barrel with the lower ni ple.` The upper and lower ports of the hea 12 are indlcated respectively at 19 and 20.

A plunger 2l closely lits the interior of the barrel but not so tightly as to prevent it from Vbeing shifted along the barrel in the manner of a piston. This plunger may be of any suitable or preferred material, the essential feature being that it is actuated lengthwise of the barrel solely by the pressure of the fluid which, in use, shifts it first in one direction 4and then in the other, and that it shall so lit the barrel as to :torce the liquid ahead of it through one head under the pressure of fluid entering the barrel throughv the other head. y

-The upper nipples of the two heads are connected by a conduit having a stop cock 22 both the plug and casing of which are preferably of glass, and the lower nipples of the two heads have suitable pipe connections with a four-way cock 23. The finger pieces or handles of the sto cock and four-way cock are indicated on yby dotted lines because when the plugmembers are in the po sitions shown bythe full lines, the said' han dies or finger pieces are in line with the fluid A conducting branches.

- The branch .of the casing of the four-way cock 23, through which Huid is to be su plied to and through the apparatus, is in icat'ed at 24, and the outlet", branch through which AHuid is delivered from the apparatus is indicated at 25. This branch 25 is shown connected by a short pipe section 26 to the hub 27 of a .hood 28 centrally arranged in which is a small nozzle 29. 'lhis latter feature of therv construction is to enable the apparatus -to be conveniently used for filling or charging a hypodermic syringe the barrel of which-may be simply ushed up under the hood 28 with the nozz e 29 entering the barrel of the. syringe.

Projecting through the head 12 and enteriiig the lbarrel 10 is a screw 30 havin a milled head 31, a gland 82 being employe to prevent the escape of fluid around the screw 30. Said screw is for the purpose of limit ing the movement of the plunger 21 towardtlie head 12. By adjusting saidscrew 30 in or out according -to the scale on the barrel 1 0, thecharge o *iluid suppliedthrough the device may be determined with precision in a manner that will presently be under stood.

In use, connection is made between the supply-branch 24 with any suitable reservoir or receiver holding the fluid under a pressure of say two or three pounds tothe square inch, the pipe which conducts the fluid to the branch 24 leading from a point, of course, below the level of the fluid in such reservoir or receiver, when such fluid is a liquid.

' lVith the parts in the position shown by full 'traveled by the plunger or' piston.

line in F ig. l, the fluid will flow through the supply branch 24 and through one of the ports of the four-way 'cock' 23 and through the pipe connections into the barrel 10 and from there through the upper conduit including the stop cock 22, the fluid being allowed to run until it begins to appear at the nozzle 29. This is simply tol lill allparts of the apparatus. It will be understoqd that during this filling operation the plunger 21 will not shift because pressure is equal on both sides. As soon however as the apparatus is filled, the stop cock is closed by turning it to the dotted line position. Since pressure continues against the right hand end of the plunger 2l and since there is nothing to prevent thev escape of fluid throu h. the port 18, the plunger will be move over close to the head 1l if it .is not already there. ow upon turning the fourway cock 28 to the dotted line position, the pressure from the supply branch 2% will be turned through the connections to the head ll so that the fluid entering the barrel at the left of the plunger 2l will force said plunger to the right as far as it is permitted to go by the adjustable stop screw 30. Since thestop cock 22 is still closed, and since the way is open from the head l2 to the delivery branch 25, the described travel or' the plunger 2l expels a volume of fluid through the nozzle 29 equal to the volume of the space Of course by setting the stop screw differently, the volume of the fluid delivered can be varied. As soon as the plunger ceases its' lsaine volume will be delivered through the nozzle 29 because this time the fluid entering through the branch 2av passes first through the port 20 of the head 12 and so increases the amount of fluid in the barrel l0 at the right of the plunger2l that the said plunger is shifted from its dotted line position to its full line position, driving ahead of it the liquid which was between it and the head ll so as to force out through the nozzle 2f) an amount of fluid equal to the volume ofthe space existing in the barrel l0 between its dotted line and full line positions.

The arrangement el.: the ports and conceases nections is such that wheny the device is tirst filled, the liquid passing out from the barrel must escape through an upper port which is located close to the upper side of the barrel, so as to prevent the trapping of any air in the barrel. As has been stated, the liquid is supplied to the branch 24 under pressure. lVith the four-way cock 23 turned so as to direct the liquid to the end of the barrel containing the adjust-ing screw, and with the stop cock open, the device will completely fill, the liquid driving all air ahead et it. As soon as a drop appears at the outlet 2.3, the stop cock 22 is closed. Then each time the four-way cock is given a quarter turn, a definite quantity of liquid will be delivered, the stop cock remaining closed. If the prcs- .sure he released, and the two cocks set as for lilling, the liquid will flow back into the supply reservoir when the latter. is below the level of the device. Therefore, when such reservoir is a bottle, with suitable pressure supplying means, the device can be used to till a small numberof syringes, even one, and the liquid remaining in the device can be run back into the. bottle, and the latter stopperechso that there is no waste what-- ever.

The device may be sterilized and connected asept-ically to a bottle oi sterile solution, used, taken down, and the bottle stoppered, without wasting or contaminating the sterile solution.

.It is to be understood that while l have illustrated and described theinvcntion in what l consider to be its preferred embodiment, I do not limit inysel't to all ol the details of construction since l may variously modify the same within the limits ol me* chanical skill, and may construct the various parts ofthe apparatus or" whatever material or materialsl may be bestsuited to thecharacteristics of. the fluid to be passed thercthrough.

l'laving now descrilied my invention, what l claim is:-

1. A. l'luid measnriiig device comprising a barrel, a freely mounted plunger in the barrel, a conduit connecting opposite ends of the barrel and having a stop cock which, when open, will permit fluid to flow l'roui one end of the barrel to the other, a four- Waycock, and conduits connecting the casing of the latter with opposite ends ol" the barrel.

2. A liquid measuring device comprising a horizontal barrel, a freely mounted plunger therein, a conduit connecting opposite ends ot the barrel and having ay stop cock which, when open, will permit liquid to il.:

tlov.v from one'end of the barrel to the other,

and connections whereby liquid. passed into' said barrel at one end will canse liquid to be ejected from the other end ot the barrel by means ol said plunger, the barrel having plunger, a conduit connecting opposite ends 'the heads respectively,one of the controlling two ports at eachy end,`one port of each pair being close to the upper side of the barrel to prevent trapping 0f air `when the device is being lilled.

3. A fluid measuring device comprising a barrel having heads each formedwith upper and lowei` ports and having nipples, a` freely mounted plunger in the barrel, a controllable connection between two ofthe-nipples of the heads respectively and a controllable connection between the other two nipples of devices being a stop cock and the other'controlling device being a four-way cock.

4. A liquid measuringdevice comprising a horizontal barrel, a freely mounted plunger therein, means for adjustably restricting the play of the plunger in the barrel, a conduit connecting opposite ends of the barrel and having a stop cock which, when open, will permit liquid to flow from one end of the barrel to theother, a four-way cock, and conduits connecting the easing of the latter with opposite ends ofthe barrel.

5. A liquid measuring. device comprising a horizontal barrel,'a freely mounted plunger therein, an adjustable screw extending into said barrel for limiting the play of the of the barrel and having a stop cock which, when open, will permit liquid to flow from one end of the barrel to the other,iafour way cock and conduits connecting the casing of the latter with opposite ends of the barrel.

(i. A liquid nleasurinv` device comprising j -inV presence o a horizontal barrel having heads each pro- 4vided with upper and lower ports, 'a freely Vmounted plunger in the barrel, two connections between said heads one of said connections having a stop cock, the other con-nection having'a four-way cock, means whereby liquid may be supplied through said fourway cock, andmeans whereby liquid may be discharged through said four-way cock.

7. A liquid measuring device comprising a horizontal barrel having heads each provided With upperand lower ports, liquid tight connections being provided between the ends of the barrel and the heads, Lclamp-V ing rods for holding the heads to 'the barrel, a freely mounted plunger in the barrel, a conduit connecting said heads and having a 4stop cock, and connections whereby liquid passed into said barrel at one end will cause liquid to be ejected through the upper port at the other end of the barrel by means of said plunger. n y

8. A liquid measuring devze comprising cause liquid to bev ejected from the other endA of vthe barrel by means of said plunger, the barrel having two ports' at each end, one port of each pair being close to the u per `Aside of the barrel to prevent trapping o air when the device is being filled.

In testimon whereof I affix my signature, two witnesses. y STANLEY D. BEARD. Witnesses: K

Enw. H. GILBERT, vEDGARC. LEAYCROFT. Y j

a horizontal barrel, a freely mounted plunger 

